A consulting firm says a high-speed passenger rail line that connects Louisville with Nashville, Atlanta and Jacksonville, Florida could be feasible.According to consulting firm HNTB, there's enough demand for the line, which could cost anywhere from $11 billion to $43 billion.According to the Florida Times-Union: The three routes were studied after an earlier study showed the feasibility of a route from Atlanta to Charlotte. That project is now in the stage of estimating the environmental impact of possible paths. Construction of any of the lines is likely to be many years in the future. But the Obama administration has made high-speed passenger rail a priority and provided funds for exploring routes.Here's a link to a Powerpoint, which was presented to Georgia's State Transportation Board yesterday. According to HNTB, there are more than 100 million people that it estimates would ride the Louisville to Atlanta route, at a one-way cost of $140.49 to $176.28.